The invention relates to a constant velocity joint, especially for steering a motor vehicle.
In particular, constant velocity joints are used in the driveline of a motor vehicle such as, for example, in the side shafts between the differential and the wheels to be driven; or in the propeller shaft between the gearbox output positioned in front, and the axle drive arranged at the rear axle.
DE 40 31 819 C1 describes a joint for large articulation angles and high torque values, for example, wherein the outer part is provided with alternating first and second outer running grooves, and the inner part is provided with alternating first and second inner running grooves. The first outer running grooves and first inner running grooves start from a first open end, and extend in an undercut-free way towards the second open end, whereas the second outer running grooves and the second inner running grooves extend from the opposed open end in an undercut-free way. The joint thus comprises tracks which alternately extend in opposite directions on the circumference. Between the outer part and inner part, there is arranged a cage. By means of a hollow spherical face, the cage is arranged centrically relative to the spherical outer face of the inner part. Furthermore, the cage, by means of its spherical outer face, is arranged concentrically relative to the spherical inner face of the outer part. The spherical inner face of the outer part is formed by first and second partial inner faces. The first partial inner faces start and extend, in an undercut-free way, from the open end from which the first outer running grooves extend in an undercut-free way. The second partial inner faces start from and extend, in an undercut-free way, from the second open end of the outer part, from which the outer running grooves extend in an undercut-free way. With the first and second outer running grooves and first and second inner running grooves alternately following one another, the first and second partial inner faces are arranged in the region of the webs between two circumferentially adjoining first and second outer running grooves in such a way that the first partial inner faces directly adjoin the first outer running grooves, and the second partial inner faces directly adjoin the second outer running grooves, and abut one another in the central region between first and second outer running grooves. The outer part is a solid part and can be produced by precision forming. The same applies to the inner part.
With regard to the foregoing joint, after the outer part has been produced to its final dimensions, it is typically broken into two individual annular segments by applying radial pressure. In this way, during assembly, after the cage has been slid on to the inner part by means of its hollow spherical face, the balls can be inserted into the windows from the outside. Subsequently, the two annular segments are mounted radially, and the unit, by means of the outer face of the outer part, is inserted into a bore of a bell. The bell supports the outer part in the radial direction. To achieve a rotationally fast connection, there are provided recesses in one of the end faces which form the open ends. After the unit has been inserted, the wall of the bell is deformed in such a way that it extends over an end face forming the open end, with material entering the region of the recesses. In this way, there is produced a rotationally fast connection. While it is true that producing such components by precision forming is less expensive than embodiments which start from a forged blank and have to be machined in a chip-forming way, the costs are still very high. This is especially true for constant velocity joints which are used for the transmission of low torque values only and at low speeds.